Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 854 insertions, 0 deletions

diff --git a/mozglue/baseprofiler/core/shared-libraries-linux.cc b/mozglue/baseprofiler/core/shared-libraries-linux.cc
new file mode 100644
index 0000000000..a12d60cf73
--- /dev/null
+++ b/mozglue/baseprofiler/core/shared-libraries-linux.cc
@@ -0,0 +1,854 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "BaseProfilerSharedLibraries.h"
+
+#define PATH_MAX_TOSTRING(x) #x
+#define PATH_MAX_STRING(x) PATH_MAX_TOSTRING(x)
+#include <stdio.h>
+#include <string.h>
+#include <limits.h>
+#include <unistd.h>
+#include <fstream>
+#include "platform.h"
+#include "mozilla/Sprintf.h"
+
+#include <algorithm>
+#include <arpa/inet.h>
+#include <elf.h>
+#include <fcntl.h>
+#if defined(GP_OS_linux) || defined(GP_OS_android)
+#  include <features.h>
+#endif
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <vector>
+
+#if defined(GP_OS_linux) || defined(GP_OS_android) || defined(GP_OS_freebsd)
+#  include <link.h>  // dl_phdr_info, ElfW()
+#else
+#  error "Unexpected configuration"
+#endif
+
+#if defined(GP_OS_android)
+extern "C" MOZ_EXPORT __attribute__((weak)) int dl_iterate_phdr(
+    int (*callback)(struct dl_phdr_info* info, size_t size, void* data),
+    void* data);
+#endif
+
+#if defined(GP_OS_freebsd) && !defined(ElfW)
+#  define ElfW(type) Elf_##type
+#endif
+
+// ----------------------------------------------------------------------------
+// Starting imports from toolkit/crashreporter/google-breakpad/, as needed by
+// this file when moved to mozglue.
+
+// Imported from
+// toolkit/crashreporter/google-breakpad/src/common/memory_range.h.
+// A lightweight wrapper with a pointer and a length to encapsulate a contiguous
+// range of memory. It provides helper methods for checked access of a subrange
+// of the memory. Its implemementation does not allocate memory or call into
+// libc functions, and is thus safer to use in a crashed environment.
+class MemoryRange {
+ public:
+  MemoryRange() : data_(NULL), length_(0) {}
+
+  MemoryRange(const void* data, size_t length) { Set(data, length); }
+
+  // Returns true if this memory range contains no data.
+  bool IsEmpty() const {
+    // Set() guarantees that |length_| is zero if |data_| is NULL.
+    return length_ == 0;
+  }
+
+  // Resets to an empty range.
+  void Reset() {
+    data_ = NULL;
+    length_ = 0;
+  }
+
+  // Sets this memory range to point to |data| and its length to |length|.
+  void Set(const void* data, size_t length) {
+    data_ = reinterpret_cast<const uint8_t*>(data);
+    // Always set |length_| to zero if |data_| is NULL.
+    length_ = data ? length : 0;
+  }
+
+  // Returns true if this range covers a subrange of |sub_length| bytes
+  // at |sub_offset| bytes of this memory range, or false otherwise.
+  bool Covers(size_t sub_offset, size_t sub_length) const {
+    // The following checks verify that:
+    // 1. sub_offset is within [ 0 .. length_ - 1 ]
+    // 2. sub_offset + sub_length is within
+    //    [ sub_offset .. length_ ]
+    return sub_offset < length_ && sub_offset + sub_length >= sub_offset &&
+           sub_offset + sub_length <= length_;
+  }
+
+  // Returns a raw data pointer to a subrange of |sub_length| bytes at
+  // |sub_offset| bytes of this memory range, or NULL if the subrange
+  // is out of bounds.
+  const void* GetData(size_t sub_offset, size_t sub_length) const {
+    return Covers(sub_offset, sub_length) ? (data_ + sub_offset) : NULL;
+  }
+
+  // Same as the two-argument version of GetData() but uses sizeof(DataType)
+  // as the subrange length and returns an |DataType| pointer for convenience.
+  template <typename DataType>
+  const DataType* GetData(size_t sub_offset) const {
+    return reinterpret_cast<const DataType*>(
+        GetData(sub_offset, sizeof(DataType)));
+  }
+
+  // Returns a raw pointer to the |element_index|-th element of an array
+  // of elements of length |element_size| starting at |sub_offset| bytes
+  // of this memory range, or NULL if the element is out of bounds.
+  const void* GetArrayElement(size_t element_offset, size_t element_size,
+                              unsigned element_index) const {
+    size_t sub_offset = element_offset + element_index * element_size;
+    return GetData(sub_offset, element_size);
+  }
+
+  // Same as the three-argument version of GetArrayElement() but deduces
+  // the element size using sizeof(ElementType) and returns an |ElementType|
+  // pointer for convenience.
+  template <typename ElementType>
+  const ElementType* GetArrayElement(size_t element_offset,
+                                     unsigned element_index) const {
+    return reinterpret_cast<const ElementType*>(
+        GetArrayElement(element_offset, sizeof(ElementType), element_index));
+  }
+
+  // Returns a subrange of |sub_length| bytes at |sub_offset| bytes of
+  // this memory range, or an empty range if the subrange is out of bounds.
+  MemoryRange Subrange(size_t sub_offset, size_t sub_length) const {
+    return Covers(sub_offset, sub_length)
+               ? MemoryRange(data_ + sub_offset, sub_length)
+               : MemoryRange();
+  }
+
+  // Returns a pointer to the beginning of this memory range.
+  const uint8_t* data() const { return data_; }
+
+  // Returns the length, in bytes, of this memory range.
+  size_t length() const { return length_; }
+
+ private:
+  // Pointer to the beginning of this memory range.
+  const uint8_t* data_;
+
+  // Length, in bytes, of this memory range.
+  size_t length_;
+};
+
+// Imported from
+// toolkit/crashreporter/google-breakpad/src/common/linux/memory_mapped_file.h
+// and inlined .cc.
+// A utility class for mapping a file into memory for read-only access of the
+// file content. Its implementation avoids calling into libc functions by
+// directly making system calls for open, close, mmap, and munmap.
+class MemoryMappedFile {
+ public:
+  MemoryMappedFile() {}
+
+  // Constructor that calls Map() to map a file at |path| into memory.
+  // If Map() fails, the object behaves as if it is default constructed.
+  MemoryMappedFile(const char* path, size_t offset) { Map(path, offset); }
+
+  MemoryMappedFile(const MemoryMappedFile&) = delete;
+  MemoryMappedFile& operator=(const MemoryMappedFile&) = delete;
+
+  ~MemoryMappedFile() {}
+
+  // Maps a file at |path| into memory, which can then be accessed via
+  // content() as a MemoryRange object or via data(), and returns true on
+  // success. Mapping an empty file will succeed but with data() and size()
+  // returning NULL and 0, respectively. An existing mapping is unmapped
+  // before a new mapping is created.
+  bool Map(const char* path, size_t offset) {
+    Unmap();
+
+    int fd = open(path, O_RDONLY, 0);
+    if (fd == -1) {
+      return false;
+    }
+
+#if defined(__x86_64__) || defined(__aarch64__) || \
+    (defined(__mips__) && _MIPS_SIM == _ABI64) ||  \
+    !(defined(GP_OS_linux) || defined(GP_OS_android))
+
+    struct stat st;
+    if (fstat(fd, &st) == -1 || st.st_size < 0) {
+#else
+    struct stat64 st;
+    if (fstat64(fd, &st) == -1 || st.st_size < 0) {
+#endif
+      close(fd);
+      return false;
+    }
+
+    // Strangely file size can be negative, but we check above that it is not.
+    size_t file_len = static_cast<size_t>(st.st_size);
+    // If the file does not extend beyond the offset, simply use an empty
+    // MemoryRange and return true. Don't bother to call mmap()
+    // even though mmap() can handle an empty file on some platforms.
+    if (offset >= file_len) {
+      close(fd);
+      return true;
+    }
+
+    void* data = mmap(NULL, file_len, PROT_READ, MAP_PRIVATE, fd, offset);
+    close(fd);
+    if (data == MAP_FAILED) {
+      return false;
+    }
+
+    content_.Set(data, file_len - offset);
+    return true;
+  }
+
+  // Unmaps the memory for the mapped file. It's a no-op if no file is
+  // mapped.
+  void Unmap() {
+    if (content_.data()) {
+      munmap(const_cast<uint8_t*>(content_.data()), content_.length());
+      content_.Set(NULL, 0);
+    }
+  }
+
+  // Returns a MemoryRange object that covers the memory for the mapped
+  // file. The MemoryRange object is empty if no file is mapped.
+  const MemoryRange& content() const { return content_; }
+
+  // Returns a pointer to the beginning of the memory for the mapped file.
+  // or NULL if no file is mapped or the mapped file is empty.
+  const void* data() const { return content_.data(); }
+
+  // Returns the size in bytes of the mapped file, or zero if no file
+  // is mapped.
+  size_t size() const { return content_.length(); }
+
+ private:
+  // Mapped file content as a MemoryRange object.
+  MemoryRange content_;
+};
+
+// Imported from
+// toolkit/crashreporter/google-breakpad/src/common/linux/file_id.h and inlined
+// .cc.
+// GNU binutils' ld defaults to 'sha1', which is 160 bits == 20 bytes,
+// so this is enough to fit that, which most binaries will use.
+// This is just a sensible default for vectors so most callers can get away with
+// stack allocation.
+static const size_t kDefaultBuildIdSize = 20;
+
+// Used in a few places for backwards-compatibility.
+typedef struct {
+  uint32_t data1;
+  uint16_t data2;
+  uint16_t data3;
+  uint8_t data4[8];
+} MDGUID; /* GUID */
+
+const size_t kMDGUIDSize = sizeof(MDGUID);
+
+class FileID {
+ public:
+  explicit FileID(const char* path) : path_(path) {}
+  ~FileID() {}
+
+  // Load the identifier for the elf file path specified in the constructor into
+  // |identifier|.
+  //
+  // The current implementation will look for a .note.gnu.build-id
+  // section and use that as the file id, otherwise it falls back to
+  // XORing the first 4096 bytes of the .text section to generate an identifier.
+  bool ElfFileIdentifier(std::vector<uint8_t>& identifier) {
+    MemoryMappedFile mapped_file(path_.c_str(), 0);
+    if (!mapped_file.data())  // Should probably check if size >= ElfW(Ehdr)?
+      return false;
+
+    return ElfFileIdentifierFromMappedFile(mapped_file.data(), identifier);
+  }
+
+  // Traits classes so consumers can write templatized code to deal
+  // with specific ELF bits.
+  struct ElfClass32 {
+    typedef Elf32_Addr Addr;
+    typedef Elf32_Ehdr Ehdr;
+    typedef Elf32_Nhdr Nhdr;
+    typedef Elf32_Phdr Phdr;
+    typedef Elf32_Shdr Shdr;
+    typedef Elf32_Half Half;
+    typedef Elf32_Off Off;
+    typedef Elf32_Sym Sym;
+    typedef Elf32_Word Word;
+
+    static const int kClass = ELFCLASS32;
+    static const uint16_t kMachine = EM_386;
+    static const size_t kAddrSize = sizeof(Elf32_Addr);
+    static constexpr const char* kMachineName = "x86";
+  };
+
+  struct ElfClass64 {
+    typedef Elf64_Addr Addr;
+    typedef Elf64_Ehdr Ehdr;
+    typedef Elf64_Nhdr Nhdr;
+    typedef Elf64_Phdr Phdr;
+    typedef Elf64_Shdr Shdr;
+    typedef Elf64_Half Half;
+    typedef Elf64_Off Off;
+    typedef Elf64_Sym Sym;
+    typedef Elf64_Word Word;
+
+    static const int kClass = ELFCLASS64;
+    static const uint16_t kMachine = EM_X86_64;
+    static const size_t kAddrSize = sizeof(Elf64_Addr);
+    static constexpr const char* kMachineName = "x86_64";
+  };
+
+  // Internal helper method, exposed for convenience for callers
+  // that already have more info.
+  template <typename ElfClass>
+  static const typename ElfClass::Shdr* FindElfSectionByName(
+      const char* name, typename ElfClass::Word section_type,
+      const typename ElfClass::Shdr* sections, const char* section_names,
+      const char* names_end, int nsection) {
+    if (!name || !sections || nsection == 0) {
+      return NULL;
+    }
+
+    int name_len = strlen(name);
+    if (name_len == 0) return NULL;
+
+    for (int i = 0; i < nsection; ++i) {
+      const char* section_name = section_names + sections[i].sh_name;
+      if (sections[i].sh_type == section_type &&
+          names_end - section_name >= name_len + 1 &&
+          strcmp(name, section_name) == 0) {
+        return sections + i;
+      }
+    }
+    return NULL;
+  }
+
+  struct ElfSegment {
+    const void* start;
+    size_t size;
+  };
+
+  // Convert an offset from an Elf header into a pointer to the mapped
+  // address in the current process. Takes an extra template parameter
+  // to specify the return type to avoid having to dynamic_cast the
+  // result.
+  template <typename ElfClass, typename T>
+  static const T* GetOffset(const typename ElfClass::Ehdr* elf_header,
+                            typename ElfClass::Off offset) {
+    return reinterpret_cast<const T*>(reinterpret_cast<uintptr_t>(elf_header) +
+                                      offset);
+  }
+
+// ELF note name and desc are 32-bits word padded.
+#define NOTE_PADDING(a) ((a + 3) & ~3)
+
+  static bool ElfClassBuildIDNoteIdentifier(const void* section, size_t length,
+                                            std::vector<uint8_t>& identifier) {
+    static_assert(sizeof(ElfClass32::Nhdr) == sizeof(ElfClass64::Nhdr),
+                  "Elf32_Nhdr and Elf64_Nhdr should be the same");
+    typedef typename ElfClass32::Nhdr Nhdr;
+
+    const void* section_end = reinterpret_cast<const char*>(section) + length;
+    const Nhdr* note_header = reinterpret_cast<const Nhdr*>(section);
+    while (reinterpret_cast<const void*>(note_header) < section_end) {
+      if (note_header->n_type == NT_GNU_BUILD_ID) break;
+      note_header = reinterpret_cast<const Nhdr*>(
+          reinterpret_cast<const char*>(note_header) + sizeof(Nhdr) +
+          NOTE_PADDING(note_header->n_namesz) +
+          NOTE_PADDING(note_header->n_descsz));
+    }
+    if (reinterpret_cast<const void*>(note_header) >= section_end ||
+        note_header->n_descsz == 0) {
+      return false;
+    }
+
+    const uint8_t* build_id = reinterpret_cast<const uint8_t*>(note_header) +
+                              sizeof(Nhdr) +
+                              NOTE_PADDING(note_header->n_namesz);
+    identifier.insert(identifier.end(), build_id,
+                      build_id + note_header->n_descsz);
+
+    return true;
+  }
+
+  template <typename ElfClass>
+  static bool FindElfClassSection(const char* elf_base,
+                                  const char* section_name,
+                                  typename ElfClass::Word section_type,
+                                  const void** section_start,
+                                  size_t* section_size) {
+    typedef typename ElfClass::Ehdr Ehdr;
+    typedef typename ElfClass::Shdr Shdr;
+
+    if (!elf_base || !section_start || !section_size) {
+      return false;
+    }
+
+    if (strncmp(elf_base, ELFMAG, SELFMAG) != 0) {
+      return false;
+    }
+
+    const Ehdr* elf_header = reinterpret_cast<const Ehdr*>(elf_base);
+    if (elf_header->e_ident[EI_CLASS] != ElfClass::kClass) {
+      return false;
+    }
+
+    const Shdr* sections =
+        GetOffset<ElfClass, Shdr>(elf_header, elf_header->e_shoff);
+    const Shdr* section_names = sections + elf_header->e_shstrndx;
+    const char* names =
+        GetOffset<ElfClass, char>(elf_header, section_names->sh_offset);
+    const char* names_end = names + section_names->sh_size;
+
+    const Shdr* section =
+        FindElfSectionByName<ElfClass>(section_name, section_type, sections,
+                                       names, names_end, elf_header->e_shnum);
+
+    if (section != NULL && section->sh_size > 0) {
+      *section_start = elf_base + section->sh_offset;
+      *section_size = section->sh_size;
+    }
+
+    return true;
+  }
+
+  template <typename ElfClass>
+  static bool FindElfClassSegment(const char* elf_base,
+                                  typename ElfClass::Word segment_type,
+                                  std::vector<ElfSegment>* segments) {
+    typedef typename ElfClass::Ehdr Ehdr;
+    typedef typename ElfClass::Phdr Phdr;
+
+    if (!elf_base || !segments) {
+      return false;
+    }
+
+    if (strncmp(elf_base, ELFMAG, SELFMAG) != 0) {
+      return false;
+    }
+
+    const Ehdr* elf_header = reinterpret_cast<const Ehdr*>(elf_base);
+    if (elf_header->e_ident[EI_CLASS] != ElfClass::kClass) {
+      return false;
+    }
+
+    const Phdr* phdrs =
+        GetOffset<ElfClass, Phdr>(elf_header, elf_header->e_phoff);
+
+    for (int i = 0; i < elf_header->e_phnum; ++i) {
+      if (phdrs[i].p_type == segment_type) {
+        ElfSegment seg = {};
+        seg.start = elf_base + phdrs[i].p_offset;
+        seg.size = phdrs[i].p_filesz;
+        segments->push_back(seg);
+      }
+    }
+
+    return true;
+  }
+
+  static bool IsValidElf(const void* elf_base) {
+    return strncmp(reinterpret_cast<const char*>(elf_base), ELFMAG, SELFMAG) ==
+           0;
+  }
+
+  static int ElfClass(const void* elf_base) {
+    const ElfW(Ehdr)* elf_header =
+        reinterpret_cast<const ElfW(Ehdr)*>(elf_base);
+
+    return elf_header->e_ident[EI_CLASS];
+  }
+
+  static bool FindElfSection(const void* elf_mapped_base,
+                             const char* section_name, uint32_t section_type,
+                             const void** section_start, size_t* section_size) {
+    if (!elf_mapped_base || !section_start || !section_size) {
+      return false;
+    }
+
+    *section_start = NULL;
+    *section_size = 0;
+
+    if (!IsValidElf(elf_mapped_base)) return false;
+
+    int cls = ElfClass(elf_mapped_base);
+    const char* elf_base = static_cast<const char*>(elf_mapped_base);
+
+    if (cls == ELFCLASS32) {
+      return FindElfClassSection<ElfClass32>(elf_base, section_name,
+                                             section_type, section_start,
+                                             section_size) &&
+             *section_start != NULL;
+    } else if (cls == ELFCLASS64) {
+      return FindElfClassSection<ElfClass64>(elf_base, section_name,
+                                             section_type, section_start,
+                                             section_size) &&
+             *section_start != NULL;
+    }
+
+    return false;
+  }
+
+  static bool FindElfSegments(const void* elf_mapped_base,
+                              uint32_t segment_type,
+                              std::vector<ElfSegment>* segments) {
+    if (!elf_mapped_base || !segments) {
+      return false;
+    }
+
+    if (!IsValidElf(elf_mapped_base)) return false;
+
+    int cls = ElfClass(elf_mapped_base);
+    const char* elf_base = static_cast<const char*>(elf_mapped_base);
+
+    if (cls == ELFCLASS32) {
+      return FindElfClassSegment<ElfClass32>(elf_base, segment_type, segments);
+    } else if (cls == ELFCLASS64) {
+      return FindElfClassSegment<ElfClass64>(elf_base, segment_type, segments);
+    }
+
+    return false;
+  }
+
+  // Attempt to locate a .note.gnu.build-id section in an ELF binary
+  // and copy it into |identifier|.
+  static bool FindElfBuildIDNote(const void* elf_mapped_base,
+                                 std::vector<uint8_t>& identifier) {
+    // lld normally creates 2 PT_NOTEs, gold normally creates 1.
+    std::vector<ElfSegment> segs;
+    if (FindElfSegments(elf_mapped_base, PT_NOTE, &segs)) {
+      for (ElfSegment& seg : segs) {
+        if (ElfClassBuildIDNoteIdentifier(seg.start, seg.size, identifier)) {
+          return true;
+        }
+      }
+    }
+
+    void* note_section;
+    size_t note_size;
+    if (FindElfSection(elf_mapped_base, ".note.gnu.build-id", SHT_NOTE,
+                       (const void**)&note_section, &note_size)) {
+      return ElfClassBuildIDNoteIdentifier(note_section, note_size, identifier);
+    }
+
+    return false;
+  }
+
+  // Attempt to locate the .text section of an ELF binary and generate
+  // a simple hash by XORing the first page worth of bytes into |identifier|.
+  static bool HashElfTextSection(const void* elf_mapped_base,
+                                 std::vector<uint8_t>& identifier) {
+    identifier.resize(kMDGUIDSize);
+
+    void* text_section;
+    size_t text_size;
+    if (!FindElfSection(elf_mapped_base, ".text", SHT_PROGBITS,
+                        (const void**)&text_section, &text_size) ||
+        text_size == 0) {
+      return false;
+    }
+
+    // Only provide |kMDGUIDSize| bytes to keep identifiers produced by this
+    // function backwards-compatible.
+    memset(&identifier[0], 0, kMDGUIDSize);
+    const uint8_t* ptr = reinterpret_cast<const uint8_t*>(text_section);
+    const uint8_t* ptr_end =
+        ptr + std::min(text_size, static_cast<size_t>(4096));
+    while (ptr < ptr_end) {
+      for (unsigned i = 0; i < kMDGUIDSize; i++) identifier[i] ^= ptr[i];
+      ptr += kMDGUIDSize;
+    }
+    return true;
+  }
+
+  // Load the identifier for the elf file mapped into memory at |base| into
+  // |identifier|. Return false if the identifier could not be created for this
+  // file.
+  static bool ElfFileIdentifierFromMappedFile(
+      const void* base, std::vector<uint8_t>& identifier) {
+    // Look for a build id note first.
+    if (FindElfBuildIDNote(base, identifier)) return true;
+
+    // Fall back on hashing the first page of the text section.
+    return HashElfTextSection(base, identifier);
+  }
+
+  // These three functions are not ever called in an unsafe context, so it's OK
+  // to allocate memory and use libc.
+  static std::string bytes_to_hex_string(const uint8_t* bytes, size_t count,
+                                         bool lowercase = false) {
+    std::string result;
+    for (unsigned int idx = 0; idx < count; ++idx) {
+      char buf[3];
+      SprintfLiteral(buf, lowercase ? "%02x" : "%02X", bytes[idx]);
+      result.append(buf);
+    }
+    return result;
+  }
+
+  // Convert the |identifier| data to a string.  The string will
+  // be formatted as a UUID in all uppercase without dashes.
+  // (e.g., 22F065BBFC9C49F780FE26A7CEBD7BCE).
+  static std::string ConvertIdentifierToUUIDString(
+      const std::vector<uint8_t>& identifier) {
+    uint8_t identifier_swapped[kMDGUIDSize] = {0};
+
+    // Endian-ness swap to match dump processor expectation.
+    memcpy(identifier_swapped, &identifier[0],
+           std::min(kMDGUIDSize, identifier.size()));
+    uint32_t* data1 = reinterpret_cast<uint32_t*>(identifier_swapped);
+    *data1 = htonl(*data1);
+    uint16_t* data2 = reinterpret_cast<uint16_t*>(identifier_swapped + 4);
+    *data2 = htons(*data2);
+    uint16_t* data3 = reinterpret_cast<uint16_t*>(identifier_swapped + 6);
+    *data3 = htons(*data3);
+
+    return bytes_to_hex_string(identifier_swapped, kMDGUIDSize);
+  }
+
+  // Convert the entire |identifier| data to a lowercase hex string.
+  static std::string ConvertIdentifierToString(
+      const std::vector<uint8_t>& identifier) {
+    return bytes_to_hex_string(&identifier[0], identifier.size(),
+                               /* lowercase */ true);
+  }
+
+ private:
+  // Storage for the path specified
+  std::string path_;
+};
+
+// End of imports from toolkit/crashreporter/google-breakpad/.
+// ----------------------------------------------------------------------------
+
+struct LoadedLibraryInfo {
+  LoadedLibraryInfo(const char* aName, unsigned long aBaseAddress,
+                    unsigned long aFirstMappingStart,
+                    unsigned long aLastMappingEnd)
+      : mName(aName),
+        mBaseAddress(aBaseAddress),
+        mFirstMappingStart(aFirstMappingStart),
+        mLastMappingEnd(aLastMappingEnd) {}
+
+  std::string mName;
+  unsigned long mBaseAddress;
+  unsigned long mFirstMappingStart;
+  unsigned long mLastMappingEnd;
+};
+
+static std::string IDtoUUIDString(const std::vector<uint8_t>& aIdentifier) {
+  std::string uuid = FileID::ConvertIdentifierToUUIDString(aIdentifier);
+  // This is '0', not '\0', since it represents the breakpad id age.
+  uuid += '0';
+  return uuid;
+}
+
+// Return raw Build ID in hex.
+static std::string IDtoString(const std::vector<uint8_t>& aIdentifier) {
+  std::string uuid = FileID::ConvertIdentifierToString(aIdentifier);
+  return uuid;
+}
+
+// Get the breakpad Id for the binary file pointed by bin_name
+static std::string getBreakpadId(const char* bin_name) {
+  std::vector<uint8_t> identifier;
+  identifier.reserve(kDefaultBuildIdSize);
+
+  FileID file_id(bin_name);
+  if (file_id.ElfFileIdentifier(identifier)) {
+    return IDtoUUIDString(identifier);
+  }
+
+  return {};
+}
+
+// Get the code Id for the binary file pointed by bin_name
+static std::string getCodeId(const char* bin_name) {
+  std::vector<uint8_t> identifier;
+  identifier.reserve(kDefaultBuildIdSize);
+
+  FileID file_id(bin_name);
+  if (file_id.ElfFileIdentifier(identifier)) {
+    return IDtoString(identifier);
+  }
+
+  return {};
+}
+
+static SharedLibrary SharedLibraryAtPath(const char* path,
+                                         unsigned long libStart,
+                                         unsigned long libEnd,
+                                         unsigned long offset = 0) {
+  std::string pathStr = path;
+
+  size_t pos = pathStr.rfind('\\');
+  std::string nameStr =
+      (pos != std::string::npos) ? pathStr.substr(pos + 1) : pathStr;
+
+  return SharedLibrary(libStart, libEnd, offset, getBreakpadId(path),
+                       getCodeId(path), nameStr, pathStr, nameStr, pathStr,
+                       std::string{}, "");
+}
+
+static int dl_iterate_callback(struct dl_phdr_info* dl_info, size_t size,
+                               void* data) {
+  auto libInfoList = reinterpret_cast<std::vector<LoadedLibraryInfo>*>(data);
+
+  if (dl_info->dlpi_phnum <= 0) return 0;
+
+  unsigned long baseAddress = dl_info->dlpi_addr;
+  unsigned long firstMappingStart = -1;
+  unsigned long lastMappingEnd = 0;
+
+  for (size_t i = 0; i < dl_info->dlpi_phnum; i++) {
+    if (dl_info->dlpi_phdr[i].p_type != PT_LOAD) {
+      continue;
+    }
+    unsigned long start = dl_info->dlpi_addr + dl_info->dlpi_phdr[i].p_vaddr;
+    unsigned long end = start + dl_info->dlpi_phdr[i].p_memsz;
+    if (start < firstMappingStart) {
+      firstMappingStart = start;
+    }
+    if (end > lastMappingEnd) {
+      lastMappingEnd = end;
+    }
+  }
+
+  libInfoList->push_back(LoadedLibraryInfo(dl_info->dlpi_name, baseAddress,
+                                           firstMappingStart, lastMappingEnd));
+
+  return 0;
+}
+
+SharedLibraryInfo SharedLibraryInfo::GetInfoForSelf() {
+  SharedLibraryInfo info;
+
+#if defined(GP_OS_linux)
+  // We need to find the name of the executable (exeName, exeNameLen) and the
+  // address of its executable section (exeExeAddr) in the running image.
+  char exeName[PATH_MAX];
+  memset(exeName, 0, sizeof(exeName));
+
+  ssize_t exeNameLen = readlink("/proc/self/exe", exeName, sizeof(exeName) - 1);
+  if (exeNameLen == -1) {
+    // readlink failed for whatever reason.  Note this, but keep going.
+    exeName[0] = '\0';
+    exeNameLen = 0;
+    // LOG("SharedLibraryInfo::GetInfoForSelf(): readlink failed");
+  } else {
+    // Assert no buffer overflow.
+    MOZ_RELEASE_ASSERT(exeNameLen >= 0 &&
+                       exeNameLen < static_cast<ssize_t>(sizeof(exeName)));
+  }
+
+  unsigned long exeExeAddr = 0;
+#endif
+
+#if defined(GP_OS_android)
+  // If dl_iterate_phdr doesn't exist, we give up immediately.
+  if (!dl_iterate_phdr) {
+    // On ARM Android, dl_iterate_phdr is provided by the custom linker.
+    // So if libxul was loaded by the system linker (e.g. as part of
+    // xpcshell when running tests), it won't be available and we should
+    // not call it.
+    return info;
+  }
+#endif
+
+#if defined(GP_OS_linux) || defined(GP_OS_android)
+  // Read info from /proc/self/maps. We ignore most of it.
+  pid_t pid = mozilla::baseprofiler::profiler_current_process_id().ToNumber();
+  char path[PATH_MAX];
+  SprintfLiteral(path, "/proc/%d/maps", pid);
+  std::ifstream maps(path);
+  std::string line;
+  while (std::getline(maps, line)) {
+    int ret;
+    unsigned long start;
+    unsigned long end;
+    char perm[6 + 1] = "";
+    unsigned long offset;
+    char modulePath[PATH_MAX + 1] = "";
+    ret = sscanf(line.c_str(),
+                 "%lx-%lx %6s %lx %*s %*x %" PATH_MAX_STRING(PATH_MAX) "s\n",
+                 &start, &end, perm, &offset, modulePath);
+    if (!strchr(perm, 'x')) {
+      // Ignore non executable entries
+      continue;
+    }
+    if (ret != 5 && ret != 4) {
+      // LOG("SharedLibraryInfo::GetInfoForSelf(): "
+      //     "reading /proc/self/maps failed");
+      continue;
+    }
+
+#  if defined(GP_OS_linux)
+    // Try to establish the main executable's load address.
+    if (exeNameLen > 0 && strcmp(modulePath, exeName) == 0) {
+      exeExeAddr = start;
+    }
+#  elif defined(GP_OS_android)
+    // Use /proc/pid/maps to get the dalvik-jit section since it has no
+    // associated phdrs.
+    if (0 == strcmp(modulePath, "/dev/ashmem/dalvik-jit-code-cache")) {
+      info.AddSharedLibrary(
+          SharedLibraryAtPath(modulePath, start, end, offset));
+      if (info.GetSize() > 10000) {
+        // LOG("SharedLibraryInfo::GetInfoForSelf(): "
+        //     "implausibly large number of mappings acquired");
+        break;
+      }
+    }
+#  endif
+  }
+#endif
+
+  std::vector<LoadedLibraryInfo> libInfoList;
+
+  // We collect the bulk of the library info using dl_iterate_phdr.
+  dl_iterate_phdr(dl_iterate_callback, &libInfoList);
+
+  for (const auto& libInfo : libInfoList) {
+    info.AddSharedLibrary(
+        SharedLibraryAtPath(libInfo.mName.c_str(), libInfo.mFirstMappingStart,
+                            libInfo.mLastMappingEnd,
+                            libInfo.mFirstMappingStart - libInfo.mBaseAddress));
+  }
+
+#if defined(GP_OS_linux)
+  // Make another pass over the information we just harvested from
+  // dl_iterate_phdr.  If we see a nameless object mapped at what we earlier
+  // established to be the main executable's load address, attach the
+  // executable's name to that entry.
+  for (size_t i = 0; i < info.GetSize(); i++) {
+    SharedLibrary& lib = info.GetMutableEntry(i);
+    if (lib.GetStart() <= exeExeAddr && exeExeAddr <= lib.GetEnd() &&
+        lib.GetDebugPath().empty()) {
+      lib = SharedLibraryAtPath(exeName, lib.GetStart(), lib.GetEnd(),
+                                lib.GetOffset());
+
+      // We only expect to see one such entry.
+      break;
+    }
+  }
+#endif
+
+  return info;
+}
+
+void SharedLibraryInfo::Initialize() { /* do nothing */
+}